Oxidation chlorinated phenols

Oxidation of phenols with chlorine dioxide or chlorine produces chlorinated aromatic intermediates before ring rupture. Oxidation of phenols with either chlorine dioxide or ozone produces oxidized aromatic compounds as intermediates which undergo ring rupture upon treatment with more oxidant and/or longer reaction times. In many cases, the same nonchlorinated, ringruptured aliphatic products are produced using ozone or chlorine dioxide. 

A facultatively anaerobic organism designated Anaeromyxobacter dehalogenans (Sanford et al. 2002) was capable of dechlorinating ortho-chlorinated phenols using acetate as electron donor—2-chlorophenol was reduced to phenol and 2,6-dichlorophenol to 2-chloro-phenol (Cole et al. 1994). A strain of Desulfovibrio dechloracetivorans was also able to couple the dechlorination of ortho-substituted chlorophenols to the oxidation of acetate, fumarate, lactate, and propionate (Sun et al. 2000). 

Dec J, J-M Bollag, (1994) Dehalogenation of chlorinated phenols during oxidative coupling. Environ Sci Technol 28 484-490. 

Wajon JE, Rosenblatt DH, Burrows EP. 1982. Oxidation of phenol and hydroquinone by chlorine dioxide. Environ Sci Technol 16 396-402. 

Wet oxidation of phenol at elevated pressure and temperature gave the following products acetone, acetaldehyde, formic, acetic, maleic, oxalic, and succinic acids (Keen and Baillod, 1985). Chlorine dioxide reacted with phenol in an aqueous solution forming p-benzoquinone and hypochlorous acid (Wajon et al., 1982). 

Dec, J., and J.-M. Bollag, Effect of various factors on dehalogenation of chlorinated phenols and anilines during oxidative coupling , Environ. Sci. Technol., 29,657-663 (1995). 

To evaluate the effect of the number of chlorines on the degradation rate constants of different chlorophenols, Table 6.2 shows the rate constants of elementary, oxidation, and dechlorination for the ratios of k2 CP/k2/l DcP and 2,4,6-tcp/ 2,4-dcp The relative rate constants are plotted against the number of sites unoccupied by chlorine atoms on the chlorinated phenols in Figure 6.3.A linear correlation between the rate constants and the number of sites available is found with a standard deviation of 0.132. Clearly, the more chlorine atoms the aromatic rings contain, the fewer sites are available for hydroxyl radical attack however, the correlation should not be used for... 

Potter, F.J. and Roth, J.A., Oxidation of chlorinated phenols using Fenton s reagent, /. Hazardous Waste Hazardous Mater., 10(2), 151, 1993. 

Tang, W.Z. and Huang, C.P, Effect of chlorine content of chlorinated phenols on their oxidation kinetics by Fenton s reagent, Chemosphere, 33(8), 1621-1635, 1996b. 

De, A.K., Chaudhuri, B., Bhattacharjee, S., Dutta, B.K., Estimation of OH radical reaction rate constants for phenol and chlorinated phenols using UV/H202 photo-oxidation, /. Haz. Mat., 64, 91-104, 1999. 

Oxidation reactions included the use of alkaline permanganate, alkaline copper(II)oxide, and aqueous chlorine (Schnitzer and Khan, 1972 Christman et al., 1989).The degradation products consisted of aromatic and aliphatic acids. Aliphatic dicarboxylic acids ranging from ethanedioic to decanedioic acids were identified. Methylation prior to oxidation prevented phenolic groups from degradation and allowed gas chromatography (GC) analysis. 

In addition to transformation by corrodable metals (such as Fe° and Zn°), bimetallic combinations of a catalytic metal with a corrodable metal (such as Pd/Fe or Ni/Fe) have also been shown to transform a variety of contaminants. In most cases, rates of transformation by bimetallic combinations have been significantly faster than those observed for iron metal alone [26,96,135-139]. Not only have faster transformation rates been observed with bimetallic combinations, but, in some cases, transformation of highly recalcitrant compounds, such as polychlorinated biphenyls (PCBs), chlorinated phenols, and DDT has been achieved [24,140,141]. The mechanism responsible for the enhanced reactivity with bimetallic combinations is still unclear however, it has been suggested that electrochemical effects, catalytic hydrogenation, or intercalation of H2 may be responsible. A likely limitation to the full-scale application of bimetallic combinations to groundwater remediation is deactivation of the catalytic surface either by poisoning (e.g., by sulfide) or by formation of thick oxide films [136,142,143]. 

Sulfonated Fe and Mn phthalocyanines are catalysts for the oxidative degradation of chlorinated phenols such as 2,4,6-trichlorophenol, a contaminant from paper mills that use chlorine for bleaching. Fe-tetrasulfophthalo-cyanine supported on poly(vinyl-4-methylpyridinium) converts 2,4,6-trichlorophenol with the K+ salt of Caro s acid, KHSO5, or H2O2 as the oxidant (112) ... 

LaRotta CE, D Elia E, Bon EPS (2007) Chloroperoxidase mediated oxidation of chlorinated phenols using electrogenerated hydrogen peroxide. Electron J Biotechnol 10 24—36... 

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